2017-2018 Influenza Season Week 48 ending December 2, 2017
December 9th, 2017During week 48 (November 26-December 2, 2017), overall influenza activity increased slightly in the United States.
- Viral Surveillance: The most frequently identified influenza virus type reported by public health laboratories during week 48 was influenza A. The percentage of respiratory specimens testing positive for influenza in clinical laboratories declined slightly.
- Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
- Influenza-associated Pediatric Deaths: Two influenza-associated pediatric deaths were reported.
- Influenza-associated Hospitalizations: A cumulative rate of 3.0 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.
- Outpatient Illness Surveillance:The proportion of outpatient visits for influenza-like illness (ILI) was 2.3%, which is above the national baseline of 2.2%. Regions 1, 4, 6 and 7 reported ILI at or above region-specific baseline levels. Three states experienced high ILI activity; Puerto Rico and three states experienced moderate ILI activity; the District of Columbia and six states experienced low ILI activity; and New York City and 38 states experienced minimal ILI activity.
- Geographic Spread of Influenza:The geographic spread of influenza in seven states was reported as widespread; Puerto Rico and 18 states reported regional activity; 18 states reported local activity; and the District of Columbia, the U.S. Virgin Islands and seven states reported sporadic activity; and Guam did not report.
